Flash 'Drink Coca-Cola' and 'Eat Popcorn' on a cinema screen for a split second, too fast to consciously see, and the audience helplessly streams to the snack bar. The 1950s experiment that supposedly proved it is the cornerstone of every belief about subliminal mind control in advertising.
That experiment was a hoax, admitted by the man who ran it. In 1957 a market researcher named James Vicary claimed he had secretly flashed those messages during a film in New Jersey and boosted Coke and popcorn sales by double digits, and the story caused a national panic about hidden persuasion. The trouble is he could never produce the data or replicate the result, and in 1962 he confessed the whole thing was essentially a publicity stunt to drum up business for his struggling firm; some researchers doubt the screening even happened as described. Decades of proper studies since have found that genuine subliminal stimuli can produce, at most, tiny and fleeting effects on someone already inclined to act, and nothing like compelling a crowd to buy snacks. So the foundational proof of subliminal advertising was made up by a man trying to sell his services. The mind-control screen was the con, not the popcorn.